From da08143b85203b581f4a6461b149186b0e9592df Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Michal=20Kube=C4=8Dek?= Date: Tue, 20 May 2014 08:29:25 +0200 Subject: [PATCH] vlan: more careful checksum features handling When combining real_dev's features and vlan_features, simple bitwise AND is used. This doesn't work well for checksum offloading features as if one set has NETIF_F_HW_CSUM and the other NETIF_F_IP_CSUM and/or NETIF_F_IPV6_CSUM, we end up with no checksum offloading. However, from the logical point of view (how can_checksum_protocol() works), NETIF_F_HW_CSUM contains the functionality of NETIF_F_IP_CSUM and NETIF_F_IPV6_CSUM so that the result should be IP/IPV6. Add helper function netdev_intersect_features() implementing this logic and use it in vlan_dev_fix_features(). Signed-off-by: Michal Kubecek Signed-off-by: David S. Miller --- include/linux/netdevice.h | 14 ++++++++++++++ net/8021q/vlan_dev.c | 4 ++-- 2 files changed, 16 insertions(+), 2 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 2dea98cbbdba..f4ad247fd324 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3153,6 +3153,20 @@ const char *netdev_drivername(const struct net_device *dev); void linkwatch_run_queue(void); +static inline netdev_features_t netdev_intersect_features(netdev_features_t f1, + netdev_features_t f2) +{ + if (f1 & NETIF_F_GEN_CSUM) + f1 |= (NETIF_F_ALL_CSUM & ~NETIF_F_GEN_CSUM); + if (f2 & NETIF_F_GEN_CSUM) + f2 |= (NETIF_F_ALL_CSUM & ~NETIF_F_GEN_CSUM); + f1 &= f2; + if (f1 & NETIF_F_GEN_CSUM) + f1 &= ~(NETIF_F_ALL_CSUM & ~NETIF_F_GEN_CSUM); + + return f1; +} + static inline netdev_features_t netdev_get_wanted_features( struct net_device *dev) { diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c index 8f025afa29fd..4181fb71ba77 100644 --- a/net/8021q/vlan_dev.c +++ b/net/8021q/vlan_dev.c @@ -678,9 +678,9 @@ static netdev_features_t vlan_dev_fix_features(struct net_device *dev, struct net_device *real_dev = vlan_dev_priv(dev)->real_dev; netdev_features_t old_features = features; - features &= real_dev->vlan_features; + features = netdev_intersect_features(features, real_dev->vlan_features); features |= NETIF_F_RXCSUM; - features &= real_dev->features; + features = netdev_intersect_features(features, real_dev->features); features |= old_features & NETIF_F_SOFT_FEATURES; features |= NETIF_F_LLTX;